TRAPEZIUM

trapezium. Trapezium, n. a figure bounded by four unequal right lines

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Tra‐pe″zi‐um (?), n.; pl. E. Trapeziums (#), L. Trapezia (#). [[NL., fr. Gr. � a little table, an irregular four-sided figure, dim. of � a table, for �; � (see Tetra-) + � foot, akin to � foot; hence, originally, a table with four feet. See Foot.]] 1. 1. (Geom.) A plane figure bounded by four right lines, of which no two are parallel.
2. 2. (Anat.) (a) A bone of the carpus at the base of the first metacarpal, or thumb. (b) A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers.